Investigation of luecomalachite green existence in Rainbow trout (Onchorhynchus mykiss) flesh in Mazandaran province

Malachite Green is extensively used as an antiparasite and antifungal agent in aquaculture. Treatment with malachite green leads to the remaining of the metabolite of this compound (luecomalachite green) in aquatic animal tissues and the production of carcinogenic compounds. The aim of this study was to investigate the presence of luecomalachite green in the flesh of Rainbow trout in Mazandaran province. Fish specimens with approximate weight of 0.5 and 1 kg were collected from 20 farms in Mazandaran province (Haraz and Tonekabon) during 2018. Luecomalachite green was measured in samples using ELISA 96-well kit produced by Europroxima Co. (Netherlands). The highest and lowest levels of luecomalachite green (0.0001 mg/kg) were obtained from samples of 0.5 kg and 0.22 mg/kg in 1 kg samlpes, respectively. In some samples of 0.5 and 1 kg collected from Tonekabon, luecomalachite green content was less than the detection limit of the kit, and the highest amount of luecomalachite green was equal to 0.0047 mg/kg in 1 kg samples. Comparison of the results of all samples showed that the lowest contamination of luecomalachite green was observed in samples of 0.5 and 1 kg of Tonekabon region and the highest level of luecomalachite green were observed in samples of 1kg of Haraz area. The results of luecomalachite green contamination in this study were lower and also in the allowed standard range compared to previous studies, this indicates the improvement of sanitary condition of aquaculture stations, effective monitoring and control strategies, use of substitutes and safe alternatives to reduce fungal contamination and hence less malachite green consumption.